Means for drilling wells



Nov. 22, 1932' J. s. ABERCROMBIE 1 MEANS FOR DRILLING WELLS Filed 001i. 19. 1951 4O J'AMEa S ABERCROMBIE VENTOR.

ATTORNEYS.

Patented Nov. 22, 1932 JAMES S. ABERCROMBIE, OF HOUSTON, TEXAS MEANS FOR DRILLING VIELLS Application filed October 19, 1931.

The invention relates to an improvement in connection with well drilling equipment and the method of using the same, and is particularly directed to a connection which is adapted for embodiment in the drill stem used in rotating the drill bit in the rotary method of drilling wells.

In the drilling of Wells it is very important that the proper amount of weight be placed upon the bit which is being used to drill the well in order that the bit will penetrate the formation and to insure that the bit is held against the surface being out. It is also important that the weight be proportioned between the draw works on the surface and the bit in the well so that excessive weighton the bit will be avoided, because if excessive weight is placed on the drill stem it will cause buckling and the bit then devi- 339 from its vertical direction. lVith present drilling operations it is necessary to use a weight indicator or other device in order to determine the amount of weight being placed upon the drill bit or it is necessary to depend upon the experience of the driller. It is also necessary to continuously lower the drill stem during the drilling operation in order that the bit may penetrate the formation. This necessitates a sliding drive connection with the drill pipe at the surface and this connection is usually known as the kelley joint or grief stem.

It is one of the objects of the present invention to improve upon the means and method of performing the drilling operation by eliminating the kelley oint or grief stem at the surface by eliminating the sliding connection betwen the rotary and the drill stem at the surface, and by providing a slip joint in the drill stem which will permit advancement of the drill bit during the drilling operation and also allow a fixed weight to be placed upon the drill bit.

Another object of the invention is to provide a slip joint for use in connection with drill stems so that the upper portion of the drill stem may remain at a constant elevation, whereas the lower portion of the drill stem connection will be free to slide vertically Serial No. 569,665.

with respect to the fixed or stationary portion.

Another object of the invention is to pro vide a sliding drive connection in a drill stem so that the bit may penetrate the formation while the major portion of the drill stem is rotating at a constant elevation.

A still further object of the invention is to provide a slip joint connection for drill stems in combination with a device for cutting off the flow of fluid through the drill pipe when the slip connection has I een extended to its maximum length.

A still further object of the invention is to provide a slip joint connection for drill stems in which the flow of fluid through the drill stem wll be cut oil when the slip joint connection has been contracted to a minimum length.

Further objects of the invention will be readily apparent when the following description is considered in connection with the accompanying drawing wherein Figure 1 is central vertica the invention applied to a drill drill bit.

Figure 2 is a broken sectional view showing a part of the device in extended. position.

Figure 8 is a vertical sectional view of the lower portion of the device showing the parts in collapsed position ready to begin drilling.

Figures 4 and 5 are sectional views taken on the lines 4l1 and 55, respectively in Figure 1.

in drilling a well with the rotary method various types of bits are used, depending upon the formation encountered. Figure 1 illustrates one common type of bit at 2. This bit is provided with a shank 3, which ordinarily receives what is known as a drill collar. the drawing of Figure 1 this drill collar is illustrated at 4, and has been slightly modified to adapt it to the present invention. Under ordinary conditions the sections of drill stem or drill pipe are then connected to this drill collar so that the bit is gradually lowered into the well'until it reaches the bottom of the well bore, whereupon it is rotated in order to continue drill'ng of the bore. The drill pipe sections are threaded section of v stem and together win tool joints and the entire device is rotated, usually in a right hand direction.

The present invention, as illustrated in Figure 1, has been inserted in the drill stem directly above the drill bit. This is one method of using the device, but it do not wish to be limited to this particular form. For purposes of illustration, however, the device will be described as shown in Figure 1.

A slip oint drill stem coupling is indicated generally at 5, and comprises an outer housing or cylinder 3, which is threaded at 7 to the drill collar, or other coupling 4:. This cylinder 6 is of considerable length, and in practicing the invention, it would probably be thirty or forty feet in length, ano carries a cap or drive bushing 8, which serves to close the upper end thereof and which cap forms a sliding fit about the periphery of the slip joint drive stem 10. This stem is arranged for telescoping engagement with the cylinder housing 6, and extends above the drive bushing 8 as at 11, to which is connected the coupling member 12, which in turn receives a section of drill pipe or drill stem 13. it is contemplated that additional sections similar to 13 will be connected to the sections shown until the proper length is obtained to allow the drill bit to rest upon the well bottom.

Inside of the cylinder 6 the slip oint drill stem is provided with a packing ring 15, which is held in position by the upper gland 16 and the lower gland 1T, well as the locking ring 18. These pars form a seal with the inner periphery 19 of the cylinder 6 and are adapted to slide inside of the cylinder to a position such as shown at 20 in Figure 3 as when the slip oint is in collapsed position, or they may be raised to a position such as 21 in Figure 2 when the device is in e: "lClQCl position.

It is to be understood that the slip joint coupling may be of any desired length and in event flush joint pipe were used and flush joint stem members the slip coupling could be made up in trebles or fourbles if desired.

When it is desired to drill a well by practicing the present invention the slip joint drive coupling will be positioned either in the drill stem adjacent the drill bit or it will be positioned at an elevation above the drill bit such that the weight of the drill stem between the tion shown in Figure 3. W hen this occurs any flow of fluid through the drill stem will be out off due to the fact that the lower end 22 of the stem 10 is beveled at 23, and is arranged to seat upon the valve member 24, which is carried by the projection 25 on the drill collar 4. The passage 26 through the drive shaft 10 is thus closed by the valve member 24, and the operator at the surface is advised that his slip coupling has been lowered far as possible. He may then raise the drill stem slightly so as to open the drill stem for circulation by raising the seat 23 away from the valve member 24. He then begins to rotate the drill stem and therefor rotates the drill bit. As the drill bit penetrates the formation, the collar twill move downwardly and carr with it the cylinder housing 6. The drill stem 10, however, re mains at a constant elevation, but is continuously rotated and causes rotation of the cylinder 6 and the bit 2 due to the fact that the stem 10 is of a non-circular section, as seen in Figure l, where the stem 10 is shown as being square.

As the rotation of the bit continues the bit penetrates the formation and the cylinder 6 gradually telescopes away from the shaft 10, and when a distance equal to the distance between the collar 4 and the drive bushing 8 has been drilled, the slip coupling will then be extended the full amount. During this interval the drill stem at the surface has remained at a constant elevation, and it has not been necessary to provide the usual sliding drive connection at the surface. When the slip coupling has been extended the maximum amount, the upper gland 16 engages the shoulder 30 on the driving bushing 8 and limits the extending movement of the parts. W hen this coupling is fully extended, it is advisable to have the driller apprised of this fact so that he will not continue rotating with the bit suspended by the slip coupling. In order to advise him that the coupling has been extended, the device has been provided with a stem 31, which is shown as being threaded into or connected with the projection 25 on the collar l. This stem 31 projects upwardly a considerable distance through the passage 26 in the stem 10, and at its upper end it carries a valve member 33, which is slidingly mounted on the upper end of the rod 31 by means of a spring 34, which is confined by a nut 35 on the rod. A suit able housing v36 is arranged over the spring and the end of the rod in order to protect the spring and the rod against erosion from the abrasive fluid being pumped through the drill stem. The spring mounting of the valve member 23 is provided so that exact fitting of the parts is unnecessary, and in the event the rod 31 is slightly different in length than the distance between the valves 33 and 24, this distance will be accommodated by the movement of the spring 34.

The valve 33, like the valve 24, seats on the end of the stem 10 and serves to close the passage 26 so that the pumps circulating the liquid through the stem will be slowed down or stalled, and in this manner the operator will be advised of a condition existing in the well.

When the operator has been advised that the coupling is fully extended, he will then add additional sections of drill stem to the upper end of the spring so that the stem 10 will be permitted to again telescope into the cylinder 6. When this telescoping movement has continued until the oint is collapsed, the seat 23 will engage the valve 24 and lowering of the stem at the surface will cease. Thus the operator is advised that the slip coupling is again collapsed and he may grip the drill stem with the rotary and begin drilling by rotation of the stem. From the foregoing description it will be apparent that the drilling operation may be carried on by merely rotating the stem at the surface while the drill bit is permitted to penetrate the formation, and that the weight on the drill bit may be accurately controlled and be maintained uniform by merely placing a suitable number of sections of drill pipes, such as sections 43 between the drill bit 2 and the slip joint coupling 5. Inasmuch as medium size drill pipe of this type has a weight of fifteen pounds per foot, a suitable amount of weight may thus be positioned between the coupling and the bit, and the operator may suspend the remainder of the drill bit from the draw works, and he is then assured that no excessive weight will come upon the bit to cause an inclination of the well bore.

During the normal drilling of the well the flow of the fluid through the drill stem is pos sible as this flow of fluid may pass through the opening 26 in the stem 10 and thence through the openings 41 in the collar 1 and into the sections of drill pipe below the slip coupling. In connection with this slip coupling it may be desirable to force the drill bit into the formation by additional pres- ;sure. This is particularly true when the well is being started, and by placing one of my improved slip couplings directly above the drill bit, as shown in Figure 1, it is then possible to anchor the drill stem 13 to the rotary and apply excessive pressure in the cylinder 6 by running the slush pumps at a high speed. The flow of fluid through the inside of the stem 13 will cause pressure in the cylinder 6, and with pumps such as those now available a pressure of fifteen hundred pounds per square inch may be obtained. This pressure would be available against the head 43 of the collar 4 and the reaction pressure would be against the gland 18 on the lower end of the stem 10. If the stem 13 were properly anchored, however, the only outlet for this pres sure would be by movement of the drill bit 2.

In this manner considerable additional pressure could be applied to the drill bit by the. slush pumps so that thebit could be forced. into the formation independently of the weight of the drill pipe on the bit.

It is contemplated that when the device is to be used in this manner a special collar. would be used to replace the collar 4', which collar would have restricted openings at 41 so that the leak of fiuid would only be suflicient to wash away the cuttings of'the drill bit. Inasmuch as the slush pump would have a greater capacity than that which could flow through the openings 41, it seems apparent that considerable pressure could be-applied to the bit.

It is contemplated in practicing the invention that the coupling may be placed directly adjacent the drill bit as seen in Figure 1 and fluid pressure applied in order to force the bit into the formation, or the coupling may be positioned as seen in Figure 3 any desired distance above the drill bit in order that sufficient weight of pipe would be available and applied to the drill bit, or the coupling could be positioned at any desired elevation in the drill stem and a combination of fluid pressure and drill pipe weight used to force the bit into the formation.

Another advantage in a slip. joint coupling of the type here disclosed is in spudding with the drill bit. Spudding is necessary when the openings such as 15 of the drill bit become clogged with mud or the cutting edges of the drill bit 46 become bailed up with gumbo or other material cut from the formation. When this occurs the bit merely slides around the well bottom and no advancement is made. It is usual for the driller to then lift the bit away from the well bottom to sharply drop it so that the bit will strike the bottom of the formation, and in this manner the materialadhering to the bit or which clogs the open-' ings is usually removed.

This spudding operation, while of advantags in removing the material from the bit, is detrimental to the drill stem as the shock to the rigid pipe sections and couplings tends to crystallize the metal and destroy the strength of the parts. With a drill stem equipped with my improved coupling, it would be possible to spud without having any detrimental effect upon the major portion of the drill pipe because the driller could raise the stem 13 gradually until the coupling were extended and then continue the raising until the drill bit 2 had been raised away from the formation a sufficient distance to perform the spudding operation. The pipe 13 at the surface could then be dropped sharply a distance considerably greater than the distance which the bit had been removed from the well bottom. The drill bit being positioned in the heavier mud in the bottom of the well would not drop as sharply as the pipe 13,

and the stem 10 would tend to telescope into the cylinder 6 faster than the drill bit drops. Thus, if the stem 13 were lowered sharply a distance greater than that which the bit raised away from the well bottom the bit would then strike the bottom of the well with considerable impact and the gland 16 would not come in contact with the drive bushing 8 so that there would be no shock except to that portion of the drill stem between the slip coupling and the drill bit. This feature Would be of material advantage in drilling formations such as those found in the Gulf coast fields where considerable gumbo is encountered and a great many drill stems are destroyed by crystallization due to spudding.

While one form of slip oint coupling has been shown and described, it is to be understood that the coupling may take on various forms in the future development of the invention, but, broadly, the invention contemplates a method of drilling wells in which the drill pipe is maintained at a constant elevation at the surface, permitting the drill bit to penetrate the formation and to apply fluid pressure as a means of forcing the drill bit into the formation.

What I claim is:

1. A slip joint drive coupling for drill stems including a housing, a drive bushing thereon, a drive stem telescopically mounted in said bushing whereby said housing and said stem may have relative longitudinal movement, and means to restrict the flow of fluid through said passage when the coupling is extended or contracted.

2. A slip joint coupling including a cylinder, a plunger therein, a fluid passage through said cylinder and plunger whereby fluid pressure tends to extend the length of said coupling, and means to restrict the flow of fluid through said passage when said plunger approaches either end of said cylinder.

In testimony whereof I hereunto aihx my signature this 16 day of October, A. D. 1931.

JAMES S. ABERCROMBIE.

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